An infant with recurrent bacterial and fungal infections is suspected to have an immunodeficiency disease. Within two days after exposure to a pathogen, the organisms have proliferated to dangerous levels requiring immediate systemic antibiotic treatment. It is unlikely that this infant has a defect in B or T lymphocyte responses to the infection because:
A) Bacteria and fungi do not require B cell or T cell responses for their clearance.
B) Bacteria and fungi are not efficiently transported to draining lymph nodes to initiate adaptive immune responses.
C) Systemic infections of bacteria and fungi are usually cleared by the spleen.
D) The defective immune response occurs too rapidly following infection to be due to a defect in B or T lymphocytes responses.
E) Adaptive immune responses require dendritic cells to take up and degrade pathogens.

Question

Quizplus · Accepted Answer

The question states that within two days after exposure to a pathogen, the organisms have proliferated to dangerous levels. This suggests a rapid response by the pathogen in the absence of an effective immune response. B and T lymphocytes are important components of the adaptive immune response, but it takes time for them to recognize and respond to a new pathogen. Therefore, it is unlikely that a defect in B or T lymphocyte responses to the infection is responsible for the recurrent infections seen in this infant.

An Infant with Recurrent Bacterial and Fungal Infections Is Suspected